Relativity acceleration paradox?

[EWright]

First, let me say that I believe Einstein's Special Theory of Relativity to be wrong. For this reason, I have signed up for this forum to challenge both my own thinking and yours. Allow me to start by proposing what appears to me to be a paradox of Einstein's perceptions.

I'm currently reading Brian Greene's "Fabric of the Cosmos". In it, Greene makes reference to Einstein's concept of acceleration (I believe acceleration applies moreso to GR but this makes no difference to the apparent paradox). He explains that if someone is free falling towards the earth that from Einstein's perspective, it is the earth that is accelerating towards him; not him towards the earth (p. 67 if u have the book).

Now, although I don't buy into this concept, it can be conceived (on an extreme stretch of the imagination) that either of the two statements can be true relative to one another. HOWEVER, if two people make the same jump at the same time from opposite sides of the earth and for good measure, let's say from the stratosphere (no, not the Vegas casino), then how can one argue that it is the earth accelorating towards both of them? This is paradocical because the earth would then have to stretch in both of their directions in order to 'reach' them both. Even in the context of one jumper, this position would assume that person somehow had the ability to remain stationary and by some force attract the earth towards him.

I do admit that I do not have a full understanding of Relativity theories. So if someone can explain to me how this is not a paradox, I would appreciate it. (And then I'll post another challenge.)

[C1ay]

I suggest you look directly at the source if you are going to try and disprove something. What he-said he-said does not agree with Einstein's chapter on The Gravitational Field where he wrote,

Originally Posted by Einstein

IF we pick up a stone and then let it go, why does it fall to the ground? The usual answer to this question is: “Because it is attracted by the earth.” Modern physics formulates the answer rather differently for the following reason...

The action of the earth on the stone takes place indirectly. The earth produces in its surroundings a gravitational field, which acts on the stone and produces its motion of fall. As we know from experience, the intensity of the action on a body diminishes according to a quite definite law, as we proceed farther and farther away from the earth....

In Einstein's own words he states that the stones falls to the Earth and not the opposite. Me thinks it will be hard for you to disprove that which he did not claim to begin with.

[EWright]

First of all, I am not attempting to "disprove" anything in this thread. Secondly, are you saying that Greene is mistaken in his understanding of Einstein's concepts? And thus, are you saying that the following scenario is false? If so, then we are on the same page, so there's no need to seem so 'confrontational'.

Greene says: "Since gravity and acceleration are equivalent, if you feel gravity's influence, you must be accelerating. Einstein argued that only those observers who feel no force at all -- including the force of gravity -- are justified in declaring that they are not accelerating. Such force-free observers provide teh true reference points for discussing motion, and it's this recognition that requires a major turnabout in the way we usually think about things. When Barney jumps from his window into the evacuated shaft, we would ordinarily describe him as accelerating down toward the earth's surface. But this is not a description Einstein would agree with. According to Einstein, Barney is not accelerating. He feels no force. He is weightless. He feels as he would floating in the deep darkness of empty space. He provides the standard against which all motion should be compared. And by this comparison, when you are calmly reading at home, you are accelerating. From Barney's perspective as he freely falls by your window -- the perspective, according to Einstein, of a true benchmark for motion -- you and the earth and all the other things we usually think of as stationary as accelerating upward. Einstein would argue that it was Newton's head that rushed up to meet the apple, not the other way around.

[C1ay]

Originally Posted by EWright

Secondly, are you saying that Greene is mistaken in his understanding of Einstein's concepts?

Yes, if Greene said what you said he said. As quoted, Einstein said in his chapter on gravity that the stone was falling to the Earth and that it was accelerated toward the Earth by it's gravitational field, not vice versa.

Originally Posted by EWright

Einstein would argue that it was Newton's head that rushed up to meet the apple, not the other way around.

Please point it out. His whole book is online here. I recall no such propositions to this effect by Einstein.

[EWright]

I'm just saying this is a point raised by Greene and that it confused me as he presented it. Perhaps then it is Greene who has misinterpreted Einstein's concepts and mistranslated them? I had hoped you all would be more familiar with the concepts and able to help me understand them better.

[C1ay]

Sorry, I haven't read it. Your experience makes me wonder if I want to.

[EWright]

It's interesting that professionals in the field can disagree to such an extent on the same subject. Upon whom then are we to rely on for our information in understanding this material from a layperson's perspective without formal training in physics?

[UncleAl]

First, let me say that I believe Einstein's Special Theory of Relativity to be wrong.

Luke Skywalker, "I don't believe it."
Yoda, "That is why you fail."

Populist treatments of mathematical models are generally crap. If there were a simpler and still valid way to do the work, even as heuristic, it would be adopted by the discipline. Organic chemists use the obviously silly LCAO approximation to do 85+% of synthesis. Idiot simple and works like a charm. For the rest we bite the bullet and respect conservation of orbital symmetry - a purely quantum mechanical concept that has never been empirically violated. Folks have tried. Real hard.

Internal inconsistencies in SR (meaning inconsistencies of a purely mathematical logical nature) automatically lead to contradictions in number theory and even arithmetic, since the mathematics of Minkowski geometry is equiconsistent with the theory of real numbers and with arithmetic. There is not a single empirical falsification of SR in any venue at any scale in 100 years of vigorous observation. If you have a wide-screen CRT TV, it is relativistically corrected to make the colors work.

Special Relativity specifically excludes gravitation. Gravitation is General Relativity. There is not a single empirical falsification of GR in any venue at any scale in 89 years of vigorous observation.

http://relativity.livingreviews.org/...1-4/index.html
http://arXiv.org/abs/gr-qc/0311039
http://www.weburbia.demon.co.uk/phys...periments.html
Experimental constraints on General Relativity

http://tycho.usno.navy.mil/ptti/ptti2002/paper20.pdf
http://www.eftaylor.com/pub/projecta.pdf
http://www.public.asu.edu/~rjjacob/Lecture16.pdf
http://relativity.livingreviews.org/...3-1/index.html
Relativity in the GPS system

http://arXiv.org/abs/astro-ph/0401086
http://arxiv.org/abs/astro-ph/0312071
http://relativity.livingreviews.org/...3-5/index.html
http://skyandtelescope.com/news/article_1473_1.asp
Deeply relativistic neutron star binaries

Your other stuff is misunderstanding. Ordering of events in either SR or GR is not Galilean, Newtonian, or Euclidean. Your entire world view is invalid except when c=infinity and h=0 are good approximations.

BTW, you have big problems with the Equivalence Principle, too, and that traces back to Galileo in 1638.

http://math.ucr.edu/home/baez/RelWWW/tests.html
Mathematics of gravitation

http://wugrav.wustl.edu/people/CMW/update98.pdf
http://www.astro.northwestern.edu/As...s/lorimer1.pdf
Equivalence Principle testing

http://arXiv.org/abs/gr-qc/0411113
http://www.npl.washington.edu/eotwas...prl83-3585.pdf
http://arXiv.org/abs/gr-qc/0301024
Phys. Rev. Lett. 93 261101 (2004)
Nordtvedt Effect

The world is more beautiful than you imagine. Imagine better.

[EWright]

Populist treatments of mathematical models are generally crap. If there were a simpler and still valid way to do the work, even as heuristic, it would be adopted by the discipline.

There is a simpler way, which is why I'm attempting to sort out some of the things that I do not understand via this forum. So I'm glad to see you all are willing to engage me on this. Einstein's mistake was basing his entire work on an initial assumption and then developing mathematical models to explain things but forcing them to fit his assumption. Thus, his models ARE perfectly accurate, but they are flawed, as are many of the concepts they are based on and the interpretations of some of the data they explain.

I know you will dispute this outright and understandably so. I understand that test after test supports SR and GR. I understand what you are saying abuot the color in my television, but if you look at my television in a mirror, blue is still blue but it's not a real T.V.

[Erasmus00]

Originally Posted by C1ay

Yes, if Greene said what you said he said. As quoted, Einstein said in his chapter on gravity that the stone was falling to the Earth and that it was accelerated toward the Earth by it's gravitational field, not vice versa.

I should point out that the quote you grabbed is from a chapter leading up to the formulation of GR. Read the rest of the section, and you'll see that the concept of a gravitational field is radically redescribed. He is talking about current understanding, not GR in that quote.

Originally Posted by C1ay

Please point it out. His whole book is online here. I recall no such propositions to this effect by Einstein.

He doesn't say that explicity, but it is implied by GR. Greene is doing what most of today's writers are doing. He attributes any GR effect to Einstein. As the theory of GR is concerned, Ewright is correct. Falling observers are indeed in inertial frames, and that is generally where calculations are done. While it seems counterintuitve that every person standing on Earth could be accelerating upward, its true, thats what metric theories (of which GR is one) describe. The force of gravity is a sort of fictious force (as much as I hate to use that phrase, so often misunderstood). Ficticious forces are forces that you see because your frame is non-inertial. Centrifugal force is one such example.
-Will